Pull-type crop harvesting machine transport system where the machine remains balanced on transport wheels and the hitch as the transport system is deployed

ABSTRACT

A pull-type crop engaging machine such as a rotary mower comprises a frame mounted on transversely spaced field ground wheels for movement with a hitch arm extending to a tractor and a transport assembly attached behind the frame for moving downwardly to a transport position so that in the transport position the hitch arm extends from one end of the frame generally in the transverse direction for towing the machine in the transverse direction. The transport includes a transport ground wheel which acts to raise the frame to pass underneath the crop engaging system to support the machine on the wheel, on a second wheel behind the frame and on the hitch. The movement of the hitch and the wheel is connected and started at a position of the hitch so that the machine remains balanced. A shield behind the frame includes a portion which moves with the transport wheel.

This application claims the benefit under 35 USC 119(e) of Provisionalapplication 61/638,864 filed Apr. 26, 2012.

This invention relates to a pull-type crop machine of the type includinga header carried on a frame to be towed behind a tractor andparticularly to an improvement relating to an arrangement by which themachine can be moved to a transport condition while remaining connectedto the towing tractor. The machine can include a cutter bar andconverging components for forming a swath or may include other cropengaging elements such as a swath turner or merger.

BACKGROUND OF THE INVENTION

Pull-type harvesting machines are typically towed from the tractor by ahitch arm which requires to be adjusted in angle relative to the frameof the machine for fine steering movements and more coarse movement tothe transport position.

Some machines are required to follow the tractor only to one side andthus include a hitch arm which is located at one end of the machine. Inothers in which the present invention is particularly effective, thehitch arm to the tractor extends from the frame over the header to ahitch coupling and can be swung by an operating cylinder from one sideof the header to the other so that the header can be located in echelonwith the tractor to one side or generally symmetrically to the otherside.

Pull-type machines of this type are well known and there are manydifferent examples manufactured by a number of different companies.

The present invention relates primarily to disk headers, otherwise knownas rotary mowers, where the design is particularly applicable. Howeverother types of headers can use the same arrangement, including sicklebar headers, where typically a reel is provided to control movement ofthe crop into the cutting knife.

The present invention relates primarily to headers which use a centertongue or hitch arm which can pivot to either side of a center line,including to a position at right angles to the center line fortransport. A center pivot machine uses a swing cylinder to steer themachine from one field position to another and the maximum allowed swingis controlled either by the cylinder stops or separate mechanical stopsbetween the hitch and rear frame. During field operation the operatorgenerally steers from one stop to the other so does not need to finetune his position very much using the cylinders. Swing angles aregenerally of the order of or slightly less than 45 degree range eitherside of the center line to help maintain machine stability.

However other types of headers can use the same arrangement, includingheaders where the hitch arm is located at one end and is generally fixedduring normal operation but can pivot to the position at right angles tothe center line for transport.

Disk headers which utilize as the cutting system a plurality of spaceddisks across the width of the header with each disk rotating about arespective vertical axis are known and widely used.

Disk headers include a support frame with a main rear beam carried on apair of spaced ground wheels with the cutter bar and conditioning systemsuspended from the frame.

Often such disk headers are relatively narrow in field width, such as 12feet or 16 feet, so that transport has been carried out simply by movingthe center tongue to a straight ahead position so that the header ispulled directly behind the tractor. In many jurisdictions this has beenaccepted even though the width of the header is still greater than theacceptable road width. However legal requirements for trailing machineson the roads are becoming more strict and users are becoming more awareof the risks of trailing over-width equipment. Also there is anincreasing requirement to provide machines of greater width which islikely to become more important when the transport problem is suitablesolved.

Some manufacturers therefore provide a trailer which allows the headerto be carried on the trailer in a direction transverse to the forwardfield direction bearing in mind that the transverse width of the headeris typically an acceptable transport width. However trailers areundesirable in that the trailer forms extra equipment which much bepurchased, in that the trailer must be towed from place to place andtherefore may often be in the wrong place or not immediately availablethus increasing transport times.

Attempts have been made therefore often in Europe where transportrequirements are more strict to provide transport wheels on the headerwhich can be deployed to the ground allowing the header to be towed onthe transport wheels in the transverse direction.

SUMMARY OF THE INVENTION

It is one object of the invention to provide header of the above typewith a transport system carried on the header which allows the header tobe quickly and conveniently moved to the transport position.

According to one aspect of the invention there is provided a pull-typecrop engaging machine for towed movement by a tractor comprising:

a frame mounted on transversely spaced field ground wheels for forwardmovement during field operation across ground carrying a crop;

a crop engaging system mounted in a transverse direction across a frontof the frame so that the frame carries the crop engaging system in theforward direction generally at right angles to the transverse directioninto the crop;

a hitch arm extending from the frame to a forward end of the hitch armarranged for attachment to a hitch connector of a tractor by which theframe is towed in the forward direction across the ground while runningon the ground wheels;

a coupling for connecting the forward end of the hitch arm to a hitchconnector of the tractor;

the hitch arm being movable so that in the field position the hitch armextends from the frame generally forwardly for towing the machine in theforward direction and in the transport position the hitch arm extendsfrom one end of the frame generally in the transverse direction fortowing the machine in the transverse direction;

and a transport assembly attached to the frame for transporting theframe and the crop engaging system carried thereon in the transversedirection towed by the tractor through the hitch arm;

the transport assembly comprising:

-   -   at least one transport ground wheel attached to the frame for        engaging the ground and supporting the frame during transport;    -   said at least one transport ground wheel being movable between a        field position in which said at least one transport ground wheel        is raised from the ground for field operation and a transport        position in which said at least one transport ground wheel is in        contact with the ground;    -   in the transport position said at least one transport ground        wheel being at a position on a forward side of a line in the        transverse direction containing the center of gravity of the        machine;    -   and an actuation arrangement for moving the hitch arm and said        at least one transport ground wheel between the field position        and the transport position;    -   the actuation arrangement being arranged to move the hitch arm        from the field position to the transport position and to move        said at least one transport ground wheel to said position on        said forward side of said line such that the machine remains        balanced while the hitch arm remains attached to the tractor        during said movement to said transport position.

Preferably the hitch is a center hitch movable relative to the framebetween a first field position inclined forwardly and outwardly toward afirst end of the frame to a second field position inclined outwardly andforwardly toward a second end of the frame.

Preferably the crop engaging system comprises a cutter bar but the sametransport system can be used on other crop engaging machines.

Preferably the actuation arrangement includes a mechanical link whichprovides at least part of a mechanical connection between the hitch armand said one of the transport ground wheels so as to communicatemovement of one to the other to provide simultaneous movement thereofrelative to the frame.

Preferably the actuation arrangement is adjustable to adjust the angularposition of the hitch arm relative to the frame when said one of thetransport ground wheels is in transport position.

Preferably there is provided a swivel mounting which is connected to theframe and carries a sub-frame supporting said one of said transportground wheels for said movement and wherein the actuation arrangementincludes an actuator for moving the swivel mounting and a link betweenthe hitch arm and the swivel mounting for connecting said movement ofthe hitch arm and said one of said ground wheels.

Preferably the swivel mounting moves in a common plane with the hitcharm and the sub-frame is mounted on said swivel mounting for movementabout a horizontal axis to lower said at least one transport groundwheel.

Preferably the swivel mounting is actuated by a cylinder connectedbetween the swivel mounting and the frame.

Preferably the link between the swivel mounting and the hitch armcomprises a cylinder operable to adjust the angular position of thehitch arm relative to the swivel mounting and relative to the frame.

Preferably the cylinder is operable to adjust the angular position ofthe hitch arm relative to the frame when said at least one transportground wheel is in the transport position.

Preferably the sub-frame carries two transport ground wheels and, in thetransport position a first one of the two transport ground wheels is ata position on a forward side of a line in the transverse directioncontaining the center of gravity of the machine and a second one of thetwo transport ground wheels is at a position on a rearward side of theline in the transverse direction containing the center of gravity of themachine and wherein said first transport ground wheel is moved to theposition on the forward side of said line by rotating the sub-frameabout an upstanding axis so as to cause the first one of the wheels topass underneath the crop engaging system.

According to a second aspect of the invention there is provided apull-type crop engaging machine for towed movement by a tractorcomprising:

a frame mounted on transversely spaced field ground wheels for forwardmovement during field operation across ground carrying a crop;

a crop engaging system mounted in a transverse direction across a frontof the frame so that the frame carries the crop engaging system in theforward direction generally at right angles to the transverse directioninto the crop;

a hitch arm extending from the frame to a forward end of the hitch armarranged for attachment to a hitch connector of a tractor by which theframe is towed in the forward direction across the ground while runningon the ground wheels;

a coupling for connecting the forward end of the hitch arm to a hitchconnector of the tractor;

the hitch arm being movable so that in the field position the hitch armextends from the frame generally forwardly for towing the machine in theforward direction and in the transport position the hitch arm extendsfrom one end of the frame generally in the transverse direction fortowing the machine in the transverse direction;

and a transport assembly attached to the frame for transporting theframe and the crop engaging system carried thereon in the transversedirection towed by the tractor through the hitch arm;

the transport assembly comprising at least one transport ground wheelattached to the frame for engaging the ground and supporting the frameduring transport;

the transport ground wheel being movable so that in transport positionthe header is carried on ground wheels on either side of the center ofgravity of the machine;

and a linkage arrangement connected between the hitch arm and themovable transport ground wheel for causing simultaneous movementrelative to the frame of the hitch arm and the movable transport groundwheel.

Preferably the frame and the cutter system are raised by downwardmovement of the transport ground wheel or wheels. However other liftingsystems can be used such as separate jacks or the field ground wheels.

Preferably the transport ground assembly is mounted between the fieldground wheels. However it can be mounted at one end to rotate around theend of the frame or over the frame.

Preferably there are two transport ground wheels which are carried on acommon sub-frame assembly attached to the frame. However the transportwheel may include only one additional wheel with one or more of thefield ground wheels acting in the transport mode.

Preferably in the transport or roading position, one transport groundwheel is at a position on one side of a line in the roading directioncontaining the center of gravity of the machine and another ground wheelused for transport is at a position on the other side of the line in thetransverse direction containing the center of gravity of the machine. Toachieve this, preferably the transport ground wheel is moved to theposition on the side of the line by passing underneath said cuttersystem. However the wheel which moves forwardly to carry the load can belocated at one end and move around the end or may pass over the headerto its forward position.

In the preferred arrangement described hereinafter there are twotransport ground wheels carried on a common sub-frame assembly attachedto the frame where the sub-frame assembly is mounted for pivotalmovement about a horizontal axis to lower the transport ground wheels tothe ground and lift the field ground wheels and for pivotal movementabout an upstanding axis to rotate said one of the transport groundwheels to said position on said forward side of the line.

Preferably the frame includes a main rear beam extending across a rearof the frame and the transport assembly is carried on the main rearbeam. However other frame arrangements may be provided which do not relyon a single main beam. The intention is that the transport assembly isattached to the existing frame structure as a separate attachableoptional component and that when attached it is carried upwardly andrearwardly of the frame so as to avoid interfering with crop harvesting.The transport assembly can also be formed integrally with the headerstructure instead of being an option.

In the preferred arrangement described hereinafter the transportassembly includes a generally L-shaped member defining a post and beamat right angles with the upstanding post mounted at its upper end forsaid pivotal movement about a horizontal axis and said pivotal movementabout said upstanding axis with said one of said transport ground wheelsat the end of the beam for movement underneath the cutter system.

Preferably in the transport position one of the transport ground wheelsis at a position on a forward side of a line in the transverse directioncontaining the center of gravity of the machine and another of theground wheels used in transport is at a position on a rearward side ofthe line in the transverse direction containing the center of gravity ofthe machine and there is provided an actuation arrangement for movingthe hitch arm and the transport ground wheel between the field positionand the transport position arranged to move the hitch arm from the fieldposition to the transport position and to move said one of the transportground wheels to said position on said forward side of said line insimultaneous operation such that the machine remains balanced on saidtransport ground wheels and said hitch arm while the hitch arm remainsattached to the tractor during said movement to said transport position.The actuation arrangement which causes the simultaneous action ispreferably a mechanical link as this is a simple construction. Howeverit may be carried out with electrical or hydraulic control of separateactuators.

In the preferred arrangement described hereinafter the mechanical linkincludes a swivel mounting which is connected to the frame and carriesthe movable transport ground wheels and the actuation arrangementincludes an actuator in the form of a cylinder for moving the swivelmounting and a link between the hitch arm and the swivel mounting forconnecting the movement of the hitch arm and the ground wheel.

Preferably the swivel mounting moves in a horizontal plane parallel tothe movement of the hitch arm and the transport ground wheel is mountedon the swivel mounting for the required downward movement about thehorizontal axis.

Preferably the swivel mounting is actuated by a cylinder connectedbetween the swivel mounting and the frame.

Preferably the link between the swivel mounting and the hitch armcomprises a cylinder operable to adjust the angular position of thehitch arm relative to the swivel mounting.

The arrangement described herein may provide one or more of thefollowing advantages:

a) Lifting is done by separate transport wheels so that no modificationof the field ground wheels is required.

b) Movement to the transport position can be effected while the tractorremains connected to the hitch and the operator remains in the cab.

c) the position of the transport wheels ensures that they cannotinterfere with crop during field operation.

The apparatus described herein can also be used for other machines whichdo not use cutters such as a merger.

The apparatus can be used particularly on pull-type sickle bar mowerswith reels as well. This is a substantial advantage using the rearmounted system where the header is raised sufficiently high to allow thewheel to pass underneath, since the other systems could not be usedsince the front wheel would have to pass through the reel.

It is desirable that all of the wheels that engage the ground when themachine is in transport are deployed from the rear crop discharge sideof the machine when the machine is in field position.

As an alternative, the lift height to allow the transport wheel to passunder the header could be obtained by lifting the machine higher withthe field wheels allowing the transport wheels to be deployed from therear following which the field wheels are withdrawn. Sickle mowers tendto lift higher than the disk mower so this would be more possible there.

The frame preferably includes a rear beam as the main structural elementbut other constructions are possible where the frame has differentcomponents providing the required structural strength.

The arrangement herein provides a construction including a mower with ahitch arm, that is a tongue that connects to the tractor, a carrierframe that carries the cutting head, lift system, field wheels which isattached to the hitch by a vertical pivot.

On a conventional machine the simplest arrangement has this wholeassembly is articulated by means of a swing cylinder directly attachedbetween the hitch and frame.

One key point about the construction herein is that it also acts toconnect the transport wheel frame to the joining link through ahorizontal pivot. Also the wheel frame cylinder that deploys the wheelframe about this horizontal pivot is connected between the joining(transport) link and transport wheel frame.

The coupling between the transport ground wheels and the frame iscarried out by pivotal movement about two axes at right angles to movethe ground wheels to the required position at the ground, the requiredorientation and the required position relative to the Center of Gravityof the frame in the transport position. This can be achieved by acoupling which is basically mounted on the frame for pivotal movementabout a vertical axis for movement in a horizontal plane as describedhereinafter and connects to the wheel subassembly for rotation about ahorizontal axis. This arrangement is preferred because it providesmovement in a plane parallel to the hitch arm movement so that a simplemechanical link can connect them. However another arrangement canprovide the coupling which is basically mounted on the frame for pivotalmovement about a horizontal axis for movement in a vertical plane andconnects to the wheel subassembly for rotation about a vertical axis.Other mounting arrangements can also be provided to obtain the functionsas defined herein.

BRIEF DESCRIPTION OF THE DRAWINGS

One embodiment of the invention will now be described in conjunctionwith the accompanying drawings in which:

FIG. 1 is an isometric view from the rear and one side of a pull-typecrop machine according to the present invention for attachment to atractor, with the tractor omitted for convenience of illustration andshowing the transport assembly in the field position.

FIG. 2 is an isometric view from the rear and one side of the pull-typecrop header of FIG. 1.

FIG. 3 is an isometric view from the rear and the other side of thepull-type crop header of FIG. 1 showing the transport assembly in apartially operated intermediate position.

FIG. 4 is an isometric view from the rear and one side of the pull-typecrop header of FIG. 1 showing the transport assembly in the transportposition.

FIG. 5 is a top plan view of the cutter bar assembly of the crop headerof FIG. 1 showing the transport assembly in the transport position.

FIG. 6 is a schematic diagram showing a first embodiment of thehydraulic circuit for operating the transport system of FIGS. 1 to 5.

FIG. 7 is a top plan view of the cutter bar assembly of the crop headerof FIG. 1 showing the transport assembly in the field position andshowing the switching system for the circuit of FIG. 6 which is omittedfrom FIGS. 1 to 5.

FIG. 8 is a top plan view of the cutter bar assembly of the crop headerof FIG. 7 showing the transport assembly in the transport position.

FIG. 9 is a first isometric view of the switching system of FIG. 7 forthe circuit of FIG. 6.

FIG. 10 is a second isometric view of the switching system of FIG. 7 forthe circuit of FIG. 6.

FIG. 11 is an isometric view from the rear and one side of the cutterbar assembly of the crop header of FIG. 7 showing the transport assemblyin the field position and showing the cooperation between the transportassembly and the rear shield.

FIG. 12 is an isometric view similar to that of FIG. 11 from the rearand one side showing the transport assembly in the partly deployedposition and showing the cooperation between the transport assembly andthe rear shield as the transport assembly moves.

FIG. 13 is a top plan view of the rear end of the hitch connected at thebeam of the frame and showing the switch valve and mechanical linkagewith the hitch at the predetermined angle which allows operation of thetransport system.

FIG. 14 is a top plan view of the hitch connected at the beam of theframe with the hitch moved to the intermediate position prior tolatching and showing the switch valve and mechanical linkage in positionto continue to allow operation of the transport system.

FIG. 15 is an isometric view of the hitch in the latched position.

FIG. 16 is schematic diagram showing a second embodiment of thehydraulic circuit for operating the transport system of FIGS. 1 to 5.

In the drawings like characters of reference indicate correspondingparts in the different figures.

DETAILED DESCRIPTION

In FIG. 1 is shown a pull type harvesting machine generally indicated at10 for attachment to a hitch 9 of a tractor (not shown) by a hitchcoupling shown schematically and generally indicated at 11. The cropharvesting machine shown is of the type which uses a cutting system 4including a row of disks 7 mounted on a cutter bar 6 as shown in FIG. 5.Thus each disk 7 is mounted on the cutter bar 6 for rotation about itsown upstanding axis 5 with the axes spaced positions across the width ofthe cutter bar. Each disk carry blades at 180° spacing so that one diskrotate 90° out of phase with the next adjacent disk thus allowing thecutting action of the blades to overlap. Arrangements of this type arewell known and many examples can be found in the prior art. The cutterbar of FIG. 5 is mounted on a frame generally indicated at 12A includingforwardly extending side support members 12B. The disks are covered by ahousing generally indicated at 13 so that the cutter system is enclosedfor safety.

Behind the cutter bar 6 is provided a conditioner 2 which can be of anumber of different types including a flail conditioner. At the rearbehind the discharge opening 9 is provided a shield 8. This can actmerely to assist in forming the swath or in respect of the flailconditioner may form a barrier to prevent high speed discharge ofmaterial which could impact surrounding persons or objects to causedamage.

The header frame 12A is mounted on a support frame including a main rearbeam 12 across the rear of the header which extends in a transversedirection TD across the width of the harvesting device to a pair of legs15 and 16 which depend downwardly from the transverse beam 12 to supporta pair of wheels 17 and 18 which carry the frame in movement across theground in the field or operating position. The wheels 17, 18 are fixedin forward direction along the forward field direction FD at rightangles to the direction TD. The wheels can be adjusted in height bycylinders 17A, 18A in a limited adjustment movement only for adjustingthe height of the frame from the ground for field operation and in alarger movement in one direction for raising the frame relative to theground wheels to a height for deployment of the transport systemdescribed hereinafter and in the other direction for lowering the frameon to the transport system and for raising the ground wheels whentransport system is in place.

The cutter bar 6 and associated components including the conventionalconditioning system of the header frame 12A are carried on the main beam12 by a suspension system generally indicated at 14 including bottomsupports 14B which allows the cutter bar to float relative to the beam12 for resting on the ground with the height of the beam 12 beingadjustable to adjust the ground pressure from the cutter bar in wellknown manner. The angle of the header on the frame can be adjusted byoptional cylinders 14A which cause the header to pivot about ahorizontal axis. This adjustment can be omitted and replaced by a simpleturnbuckle arrangement if the tractor does not carry enough hydrauliccircuits to support this function.

A hitch arm 19 is attached to the transverse beam 12 by a mountingbracket 20 connected on top of the beam 12. In the embodiment shown thebracket 20 is located at the center of the beam 12 so that the hitch arm19 can pivot about a vertical pivot pin 20A to one side (FIG. 1) or theother side (FIG. 2) under control of a cylinder 21. It will beappreciated that movement of the hitch arm 19 to one side acts to towthe harvesting machine in echelon to one side of the tractor and pivotalmovement of the hitch arm 19 to the other side tows the harvestingmachine in echelon to the opposite side. The hitch arm can also belocated centrally in which case the harvesting machine is towed directlybehind the tractor generally in a transport position. The cylinder 21can also be used in some cases to steer fine movements of the headerbehind the tractor to locate the position of the header across the rearof the tractor and is used in the movement to transport as describedhereinafter.

The above arrangement of pull type disk mower is well known and manyexamples can be found in the prior art including many patents by thepresent Applicants, to which reference may be made for further detailsnot described herein.

In the present arrangement there is provided an additional transportdevice 30 attached to the beam 12 which in general allows the header tobe lifted to raise the field ground wheels 17, 18 from the ground and tosupport the header on transport ground wheels 31 and 32 for transportingthe frame 12A and the cutter system 4 carried thereon in the transversedirection TD towed by the tractor through the hitch arm 19.

As previously described, in the field position the hitch arm 19 extendsfrom the frame generally forwardly for towing the machine in the forwarddirection FD. In the transport position the hitch arm is turned so thatit extends from one end 12C of the frame generally in the transversedirection TD for towing the machine in the transverse direction.

The transport assembly 30 includes the two transport ground wheels 31and 32 attached by a sub-frame 33 to the rear main beam 12 of the frame12A for engaging the ground oriented in the transport direction andsupporting the frame 12A and header during transport.

In general, the transport ground wheels 31, 32 are movable between afield position shown in FIGS. 1 and 2 and a transport position shown inFIGS. 4 and 5.

In the field position, the transport ground wheels are supported on thesub-frame 33 raised from the ground for field operation. The sub-frameand the wheels 31, 32 are carried from the main beam 12 so that theloads from the header are transferred through existing structuredesigned to carry the loads. The sub-frame and the wheels 31, 32 arecarried from the main beam 12 so as to extend upwardly and rearwardlyfrom the main beam. In this way the whole transport system is supportedin the field position at a location where the transport system does notinterfere with the crop either in front of the header during cutting, orduring movement of the crop through the header after cutting or in theswath laid on the ground after processing.

In the transport position, the transport ground wheels 31, 32 are incontact with the ground with the field ground wheels 17, 18 lifted fromthe ground. In this way the field ground wheels are not used duringtransport and thus remain unchanged from their conventional operationand in the same orientation relative to the machine. There is norequirement to provide an increased height adjustment nor to provide aswivel mounting which changes the orientation.

In general, the transport assembly 30 is arranged to raise the frame 12Aand the cutter system 5 by lowering the ground wheels 31, 32 to theground and thus raising the frame and cutter bar to a height in whichone of the transport ground wheels 32 can pass underneath the cuttersystem to a position in front of the cutter bar 6 and underneath thecovers 13. That is the frame and the cutter system are raised bydownward movement of the transport ground wheels 31, 32 to the positionshown in FIG. 3 where the wheels roll over the ground underneath themain beam 12 to raise the main beam to a point where the ground wheels17, 18 are off the ground.

The transport ground wheels 31, 32 are carried on a common sub-frameassembly 33 attached to the beam 12 of the frame 12A so that both thetransport ground wheels are mounted between the field ground wheels 17and 18 generally centrally of the beam 12.

The sub-frame 33 is generally L-shaped with a leg 33A which isupstanding in the position of FIG. 3 and a horizontal beam 33B. Thewheel 31 is located close to the bottom of the leg 33A with the wheel 32at the opposite end of the beam 33B. The leg 33A is formed of twoparallel members for stability.

In the transport position the transport ground wheel 32 is at a positionon a forward side of a line COGL (FIG. 5) parallel to the transversedirection TD containing the center of gravity of the machine and thetransport ground wheel 31 is at a position on a rearward side of theline COGL. The transport ground wheel 32 is moved to its position on theforward side of the line COGL by passing underneath the cutter system 4.

The transport ground wheels 31, 32 are carried on the common sub-frameassembly 33 attached to the beam 12 where the top end of the leg 33A ofthe sub-frame assembly 33 is mounted for pivotal movement about ahorizontal pivot pin 33C defining an axis of rotation parallel to thebeam 12 to lower the transport ground wheels to the ground and lift thefield ground wheels. Movement of the sub-frame 33 about the axis of thepin 33C is effected by a cylinder 33D. The pivot pin 33C is carried on aswivel mounting 35 which is connected to the frame for pivotal movementabout an upstanding pin 36 defining a vertical pivot axis where the pin36 is carried on the beam 12 and the bracket 20 attached thereto. Thusthe pivot pin 33C rotates through approximately 90 degrees from thefirst position parallel to the beam 12 shown in FIG. 1 to the positionshown in FIG. 4 where the pin 33C is at right angles to the beam 12.

Thus the swivel coupling and the sub-frame 33 define a vertical axis ofrotation defined by the pin 36 for rotation of the wheel 31 to thetransport direction and for movement of the wheel 32 to the forwardposition. Also the swivel coupling defines a horizontal axis of rotationdefined by the pin 33C for the sub-frame to move downward to lower thewheels 31, 32 to the ground.

In operation therefore the coupling of the ground wheels 31 and 32carries the wheels from the main beam 12 and provides movement relativeto the beam to move the wheels downwardly while remaining parallel tothe forward direction. The beam 33B then rotates relative to the beam 12and thus turns both wheels 31 and 32 to the transport direction whilecarrying the wheel 32 underneath the header including the cutter systemto the transport position as described above.

While the description herein is presented in respect of the beam 12 ofthe header, typically during rotation the transport wheels stayrelatively stationary on the ground and the front of the hitch staysstationary relative to the tractor while the beam 12 and header frame12A carried by the beam rotate into place above the transport wheels.This is desirable since the header does not move much relative to thetractor so that transport can be engaged in minimal space. It also makesfor smooth operation with minimal tire scrubbing.

A channel 33F welded onto the top of the beam 33B at the end adjacentthe wheel 32 provides an engagement member for butting against thecutter bar 6 which is located underneath the cutter bar 6 and provides arest point for the header to take some load, in both the vertical andtransport directions. This can be merely a resting point or made moreelaborate in such as by latching arrangements to provide coupling withthe cutter bar.

As shown in FIG. 5, the beam 33B is only of a length to locate the wheel32 just in front of the cutter bar 6 and underneath the cover 13. Theheight of the cutter bar ensures that the wheel does not interfere withany component as it rotates and carries the header. The beam is of alength which does not present the wheel 32 in front of the header. Thisis due to practical limitations of its length which would otherwisecause interference with the field wheel 17. Also it is desirable tolocate the transport beam 33B at a position in transport which is behindthe center of gravity of the implement so that there is some weight onthe tractor drawbar.

The movement of the sub-frame 33 about the vertical pin 36 is actuatedby a cylinder 37 connected between the swivel mounting 35 and the beam12 at a coupling 38. The movement of the swivel mounting 35 iscommunicated to the hitch arm 19 by the cylinder 21 which extendsbetween the hitch arm 19 and the swivel mounting 35. This acts toconnect the hitch arm and the ground wheel 32 while the header and beam12 move relative to these elements.

Thus in the transport position, the transport ground wheel 32 is at aposition on a forward side of a line in the transverse directioncontaining the center of gravity of the machine and the other of thetransport ground wheels is at a position on a rearward side of the linein the transverse direction containing the center of gravity of themachine. The actuation arrangement provided by cylinder 37 and thecylinder link 21 acts to move the hitch arm and the transport groundwheels between the field position and the transport position insimultaneous operation such that the machine remains balanced on thetransport ground wheels 31, 32 and on the hitch arm 19 while the hitcharm remains attached to the tractor during the movement to saidtransport position.

The swivel mounting 35 forms in effect a universal coupling and movesitself in a horizontal plane about the vertical pivot pin 36 whichmaintains the cylinders 37 and 21 in the same plane common pane with thehitch arm 19 while the transport ground wheels are mounted on the swivelmounting 35 for the downward deployment movement actuated by thecylinder 33D.

Turning now to FIG. 6, there is shown a schematic of an embodiment ofthe circuit for controlling the operation of the hydraulics of theheader from the tractor T. The tractor includes a first and a secondhydraulic fluid supply circuit 40, 41 each having a control valve 40V,41V operable to supply fluid pressure at either one of a pair of ports40A, 40B of the supply 40 and 41A, 41B of the supply 41 with the fluidreturning to the other of the ports as controlled by the valve.

In this embodiment, the steering cylinder 21 which is a double actingcylinder is controlled in steering action by the supply 40.

In this embodiment the lift cylinders 17A, 18A are on the same circuitfrom the supply 41 as the transport actuation cylinders 37 and 33D. Aswitching valve 43 is provided which includes a plunger 44 operated by amechanical linkage 45 described hereinafter and shown in FIGS. 7 to 10.The valve 43 has inlet ports 43A and 43B and operates to select outputport 43C and 43D or ports 43E and 43F depending on the position of theplunger 44.

In a depressed position of the plunger, the valve switches the flow toports 43E, 43F to operate the transport deployment cylinders 37 and 33D.

In the released position of the plunger, the valve switches the flow toports 43C, 43D to operate the lift cylinders 17A, 18A which areconnected in series in a master/slave configuration.

The deployment cylinders 33D and 37 are operated sequentially by twoseparate sequence valves 46A, 46B. One sequence valve ensures thatcylinder 33D fully extends before allowing cylinder 37 to retract, forplacing the header in transport configuration. The other sequence valveensures that cylinder 37 fully extends before allowing cylinder 33D toextend, for placing the header in field configuration.

Thus in this arrangement, the lift cylinders 17A, 18A and transporthydraulics 37, 33D are on the same circuit and the steering cylinder 21is on a separate circuit. This arrangement is effective in anarrangement where the tractor has only two supply circuits 40 and 41. Ina situation where a third circuit (not shown) is available, this can beused for the cylinder 14A to tilt the header.

The mechanical linkage 45 includes a pair of guide arrows 47, 48 whichprovide a visual indication to the driver when the linkage is in therequired location to cause the depression of the plunger 44. One of thearrows 48 is connected to the member carrying the switch 43 and theother 47 is connected to the mechanical linkage 45 so that the arrowsbecome aligned only in a predetermined angular position of the hitch arm19 relative to the beam 12 and are maintained aligned during movement ofthe components as described hereinafter.

As shown in FIGS. 7 to 10, the valve 43 is carried on a horizontal arm49 pivotal around the axis of the pin 20A of the hitch arm 19. The arm49 also carries the lower arrow 48. The angular position of the arm 49around the axis of the pin 20A is controlled by a link 52 attached to anarm 53 carried on the swivel coupling 35.

A slotted link 42 with a slot 42A is connected to the actuator 44 of thevalve 43 with a bolt 44A that can pivot. The slotted link 42 is alsoconnected to a finger 51 that has a pivot bolt 51A that connects to theslot of the slotted link 42 with freedom to slide and turn within theslot. When the pivot bolt 51A of finger 51 hits the end of the slot 42Ain the slotted link 42 any further travel will cause the mechanism todepress the valve actuator 44 to depress the spring return plunger thatis part of the valve 43 and switch the valve 43 from lift function totransport function. At all other location in the slot the valve actuatorthe valve remains in lift mode. The device uses two overlying slottedlinks to prevent binding of the sliding and pivot connections of the pin51A. The link 42 has an additional flange 42F to mount the indicatorarrow 47. The arrow 48 is carried on the arm 49 so as to move with theswitch 43.

The mechanical linkage 45 thus comprises the arm 49 that carries theswitch 43 and is caused to rotate with the swivel mounting 35 around thepin 20A; the finger 51 which carries the pin 51A and is mounted on theend of the hitch 19 to move with the hitch and the link 42 carried onthe pin 44A which carries the slot 42A and acts to depress the plungerthrough the pin 44A when the pin 51A reaches the bottom of the slot. Inthis way, these components act to allow operation of the transportsystem by operating the switch 43 only when the switch is at therequired angle to the beam 12 and acts to maintain the switch operatedwhile the hitch and transport system move relative to the beam 12 to theintermediate position before the transport position.

The plunger 44 is operable by the pin 44A which is pushed forwardly todepress the plunger when the pin 44A reaches the end of the slot 42A.The location of the switch 43 on the arm 49 as controlled by the link 52is arranged relative to the push rod link 42 so that the plunger isdepressed only when the hitch arm is at or closely adjacent apredetermined angle relative to the beam 12.

The geometry of the link 52 relative to the arm 49 is arranged to movethe switch 43 so that its plunger remains depressed as the swivelcoupling 35 and the hitch arm 19 are simultaneously moved by operationof the cylinder 37 during the movement to the transport position.

The position of actuation is chosen so machine remains stable duringtransport deploy. The position of actuation is an intermediate positionof movement of the hitch and not at one end limit. That is the systemdoes not operate as a sequencing system where the position is at one endof a movement of a first component of the machine so that the nextaction can only take place after the first component has completed itsmovement. The linkage operating the switch 43 is directly actuated bythe hitch of the machine as opposed to other components such as thelifting of the ground wheels or as part of the transport actuation. Thatis the position of the hitch which actuates the switch 43 enables themovement to transport to be initiated and is itself not a part of thetransport actuation.

The criteria for choosing the range of angles in which transport isactive include:

To avoid the extreme range to one side of the machine that would causeinstability.

To keep the lift active at the two extremes of movement of the frontswing cylinder since these are the normal field operating positions forthe hitch.

To keep lift active in straight ahead position in case somebody wants tocutting here for recutting, opening field etc.

To be small so that lift is available to the operator in the majority ofhitch positions for ease of field operation.

So that in the preferred embodiment the rear transport cylinder cancomplete its movement and move the transport wheels to be in properposition under the machine before or when the hitch reaches thetransport position, that is it hits a stop).

So that in the preferred embodiment the operator can finish moving thehitch from the intermediate position to the latch position with thefront cylinder so that the valve can switch from transport to liftfunction and allow the system to retract the wheels, lower the headeronto the stop, close the latch and then reverse these steps fordisengaging transport.

The following steps are undertaken to place the header in transportmode:

1. Preferably move the tractor to a position to line up the hitchparallel with tractor.

2. Operate steering cylinder 21 using the valve controlled supply 40 torotate header so that the top arrow 47 is not pointing at the bottomarrow bracket 48. In this position, the plunger 44 of the valve 43 isspring returned and not depressed, allowing the lift cylinders 17A, 18Ato be operational.

3. Fully extend the lift cylinders using the supply 41 from the tractorso that the header is lifted off the ground by lowering the wheels 17,18 to the bottom position.

4. Operate the steering cylinder 21 using the supply 40 to rotate theheader until arrows 47, 48 are lined up at the required predeterminedangle of the hitch arm relative to the beam 12. In this position theplunger 44 is fully or partly depressed allowing the transport circuitincluding the cylinders 37 and 33D to be operational and to disconnectthe lift cylinders. At the predetermined position, the header beam 12 isroughly 16 degrees past being perpendicular with the hitch arm 19. Thiscan be adjusted. The switching between functions typically occurs whenthe plunger is partially depressed thus defining a range of anglesrather than one specific angle where the transport is active.

5. Operate the supply 41 to fully extend the transport deploy cylinder33D and fully retract transport swing cylinder 37. As stated previouslythe transport deploy and swing cylinders are plumbed in parallel withthe sequence valve 46 set to, for example, 2000 psi on the line to theswing cylinder 37. The transport deploy cylinder 33D thus fully extendsand reaches the 2000 psi pressure opening up the sequence valve,allowing oil to go to swing cylinder 37 and fully retract it causing thesimultaneous movement of the transport sub-frame 33 and the hitch arm19. The above mechanical linkage defined by the arm 49 carrying theswitch 43, the link 52 and the finger 51 carrying the link 42 ensuresthat the plunger 44 remains depressed during this movement. We have apressure setting that when exceeded switches the function. It needs tobe high enough to fully lift the machine consistently and but below thetractor operating pressure so that the swing cylinder can be operated.The machine could however be made to operate at lower setting byincreasing cylinder bore or changing geometry.

6. The movement caused by the cylinder 37 is arranged so that the hitchremains short of its position shown in FIG. 8 at the end of the framewhere a latch element 19L on the hitch arm 19 is arranged to engage alatch element 12L on the beam 12. This halting of the hitch at the shortposition allows the lift cylinders to be reengaged by moving the hitchwith the steering cylinder 21 and also avoids the necessity for ensuringthat the hitch and transport wheels reach their target positions exactlyat the same time. Then front steering cylinder 21 is used to completethe movement to the transport position. During this movement the linkageswitches the hydraulic valve so that the lift cylinders are activated.The operator then uses the lift cylinders to lower the header ontosupport 33F which at the same time raises the field wheels for maximumground clearance and at the same time closes the hydraulic latch.

Thus for transport, if the hitch arm is not in the correct position fortransport when it has been moved by movement of the swivel coupling 35caused by the cylinder 37, the cylinder 21 is operated to move the hitcharm to the required position.

With the wheels in the transport position, the header can be loweredrelative to the beam 12 by operation of the cylinders 17A, 18A so as todrop the cutter bar onto the beam 33B extending across underneath thecutter bar to provide stability and to reduce the cantilever loads. Theconnecting bracket 33F can be provided to improve connection betweenthese elements.

7. At this position (FIG. 14), the supply 40 is activated to retract thesteering cylinder 21 until the header engages the latch 12L on beam 12.In this position the predetermined cooperating angle between the switch43 and the mechanical linkage is changed to release the plunger 44 sothat the lift cylinders 17A, 18A are again activated and areoperational.

8. The lift cylinders are retracted to sit the header cutterbar ontransport leg bracket 33F and to raise the wheels 17, 18 to theirhighest position to clear obstacles.

The reverse operation from transport to field mode is carried out asfollows:

1. Preferably line up the hitch arm parallel with the tractor.

2. Disengage the frame latch 191_, 12L. This can be done at the latchmanually or there may be provided an electrically operated release inthe cab. However more preferably this is carried out using the latchcylinder 12 M shown in FIG. 15 and shown in FIG. 6 in the same circuitas the lift cylinders 17A, 18A.

3. Fully extend the lift cylinders 17A, 18A.

4. Operate the steering cylinder 21 until the arrows 47, 48 are lined upindicating that the mechanical linkage has depressed the plunger tooperate the switch 43.

5. Fully extend the transport swing cylinder 37 and fully retract thetransport deploy cylinder 33D in sequence as explained above.

For a center pivot machine angle the hitch must move relative to machinecenterline to reach transport position is in the order of 90 degreeswhile the normal working range of the front swing cylinder is in theorder of 45 degrees from centerline.

In an alternative arrangement, movement of the hitch to rear frame couldbe accomplished by extending the range of the front cylinder and havingit connected to the rear frame like a conventional machine rather thanthrough the swivel coupling. A problem is the cylinder cannot be allowedto fully extend in field mode with field wheels carrying the machine orthe machine will be unstable. In operation the operator would have todeploy the transport wheels into transport position or a stableintermediate position before fully extending the cylinder so that themachine remains stable. A control linkage or proximity sensor control aspreviously described could be used to prevent the swing cylinder fromoperating at unstable hitch to machine positions in field mode and/orswitch hydraulic function between steering and transport operation. Aremovable stroke limiting stop such as a rod sleeve or stop betweenhitch and frame could be provided for the operator to reduce steeringcylinder so the stroke is reduced to the order of 45 degrees forconvenience of operation during field mode.”

With the link system provided by the cylinder 37 and swivel mounting 35connected to both the hitch 19 and beam 12 it can be arranged so thatsome or all of the movement between hitch 19 and beam 12 is provided byactuating the rear cylinder 37 since both the hitch and transport swingrelative to the beam 12 and header frame 12A. This way no additionalrange to the front cylinder 21 is required. When the transport rearcylinder 37 swings into field mode, the front cylinder 21 functions asnormal on a center pivot machine which has no transport system.

It should be noted that a mechanical stop between the hitch 19 and beamis also an important part of the position control using the preferredembodiment. This allows the operator to fully actuate the rear cylinder37 and then finish using front cylinder 21 until hitting the stop.

An alternative to the mechanical stop would be to provide an indicatoror control so the operator starts with the front swing cylinder 21 inthe correct position before engaging the transport.

In the preferred embodiment the hitch actually latches to the rear frameat the stop. This not only does not allow the operator to inadvertentlyoperate the swing cylinder 21 and 37 during travel in transport positionbut also provides a redundant connection so that if either of thecylinders 21 and 37 failed mechanically the latch would still hold.

In the preferred embodiment described above, the system activates thelatch cylinder 12M with the lift so that when the operator drops theheader onto the transport frame and at the same time lifts the fieldwheels the latch 12L is activated. This has the benefit of forcing theoperator to lift the header from the support before swinging out oftransport.

In an alternative arrangement, since the two fairly sophisticatedcontrol mechanisms described above are not strictly necessary for thearrangement to operate, there can be provided a simplified set of steps.Simply the system needs to 1) deploy the transport wheels under theframe using the cylinder 33D and 2) Swing the machine into transportposition using the rear cylinder 37.

For a center pivot machine, it is preferable that the rear cylindercompletes its turn so that the third step of completing the motion withthe front swing cylinder 21 has been added. This requires the operatorto start in a range that allows the rear cylinder to complete itsactuation. This is made much easier by adding a visible mechanical stoplatch 12L at the transport position.

An alternative would be to provide an indicator so the operator couldfirst position the hitch 19 in the correct position. Then the rear swingcylinder 37 can complete its actuation at the correct transportposition.

Another reason for the sophisticated control is that with the hitchswung all the way to the same side that the transport wheel at the endof the “L” is on, when the transport wheels first lift the machine offthe ground the machine becomes unstable. This is because the COG isahead of the triangle defined by the wheels and hitch. Limiting therange of hitch angles that the transport is operable in prevents this.Another solution might be to add ballast to move the center of gravityrearward or on other types of machines this may not be a problem at all.

In the preferred embodiment the latch cylinder is plumbed in parallel tothe lift cylinder so it automatically opens when you extend the liftcylinders to raise the header off of support 33F. This feature alsoprevents you from being able to turn the transport without lifting theheader off the support which can cause issues since the support couldget caught on the conditioner.

Turning now to FIGS. 7, 11 and 12 the shield 5 is shown in more detailand includes a top panel formed by a center section 5A and two sidesections 5B, 5E all aligned across the frame and defining common rearedge spaced rearwardly from the beam 12. The sections are separate witheach of the inner side edges of the two wing sections having anoverlapping edge strip 5D lying on top of an edge portion of the centersection. The center section overlaps the sides to tension the entireshield when in field mode thus reducing shield vibration.

Outside the wing sections is provided a pair of depending side panels 5Cand 5F which prevent deflection to the sides. The wing sections and theside panels are fixed to the frame and to each other to remain in fixedposition during operation. The center section 5A is connected to the leg33A of the sub-frame 33 by a link 5L which is attached by a bracket 5Pto the upper face of the center section 5A and by a bracket 5Q to theforwardly facing surface of the leg 33A. The link 5L comprises a rigidleg 5R connected to the brackets by universal couplings 5T and 5S.

The provision of the shield cover is an ISO safety standard requirementfor machines equipped with flail type conditioner due to higherdischarge than roll conditioner. When the header is set in transportmode, the transport frame 33 drops down and swings sidewaysapproximately 90 degrees. The shield panel thus consists of three pieceswith center piece attached to the transport frame following it as itgoes through the drop down and swing motions. In order for the shield tostay attached to the transport as it swings, the double u-joint link isused as described above.

Turning now to FIG. 16, there is shown an alternative embodiment forcontrolling the operation of the hydraulic systems from the supplies 40and 41 of the tractor in replacement for the circuit of FIG. 6. Many ofthe components are common and hence use the same reference numbers sothat the description thereof will not be repeated here.

In this embodiment the switch 43 is connected to the steering cylinder21 on one circuit and to the transport cylinders 37 and 33D on the othercircuit. In this embodiment there is no mechanical linkage whichcontrols the plunger 44 but instead it is operated by a switch 60 in acontrol panel 59 manually operable in the tractor cab to supply powerfrom a tractor power supply P to the switch 43. The switch 60 is a twoway switch operable between the two modes of hitch steering 61 andtransport 62. In order to prevent the tractor operator selecting themodes at the wrong times, there is provided a pair of warning lights 63and 64 and relays 66 which are operable in response to proximity sensors65A, 65B which detects angular positions of the hitch arm 19. Thus aplate can be carried on the hitch arm 19 which comes into proximity withthe sensor 65A and indicates when the hitch arm is at the predeterminedangle defined above by illuminating the light 63 and indicates when thehitch arm is adjacent to the predetermined angle defined above byilluminating the light 64. In this embodiment the arrangement is suchthat the steering cylinder and transport hydraulics are on the samecircuit 41 and the lift cylinders are on the separate circuit 40.

Thus there are two proximity sensors 65A, 65B, one for each indicatorlight. One sensor and light tells the operator that the header anglerelative to the hitch is within range to start the transport deployment.The other sensor and light detects the allowed rotational range of theheader when it goes into transport mode. It alerts the operator thattransport function is available and keeps the hydraulic switch engagedto supply oil to the transport cylinders for the transport sequence.

The operation is as follows for placing the header in Transport Mode:

1. Fully extended lift cylinders using the supply 40 so that the headeris lifted off the ground by extending the wheels to their bottomposition.

2. Set the switch 60 to “STEERING” 61. Typically the switch will be inthis position during normal use of the header in the field.

3. Operate the supply 41 to move the steering cylinder to rotate headeruntil firstly the green light “TRSP START” 63 is illuminated indicatingthat the header position relative to the hitch arm is at the requiredposition to engage transport. At this position, the amber light “TRSPAVAIL” 64 should also be illuminated indicating the header positionrelative to the hitch arm is in the rotational range that the transportis allowed to operate in.

4. Set switch 60 to “TRANSPORT” 62 so that the transport system isactuated by the supply 41 through the valve 43 so as to fully extend thetransport deploy cylinder 33D and fully retract the transport swingcylinder 37. In this way the wheels are moved to the transport positionand the hitch arm is moved to a position adjacent to but spaced from thelatch 12L.

6. Set the switch 60 to “STEERING” 61 so that the valve 43 is springreturned to cause actuation of the steering cylinder 21 so that thehitch steering is operational.

7. Retract steering cylinder until header latch member 19L engages latch12L on the carrier frame.

8. Retract lift cylinders 17A, 18A using the supply 40 to sit the headercutterbar on the transport leg bracket 33F.

The operation is as follows for placing the header in field Mode:

1. Disengage carrier frame latch to hitch.

2. Fully extend the lift cylinders.

3. Set switch 60 to “TRANSPORT” 62 so as to operate the valve 43 fromsteering cylinder to transport sequence valve circuit.

4. Fully extend transport swing cylinder and fully retract transportdeploy cylinder.

5. Set rocker switch to “STEERING”.

1. A pull-type crop engaging machine for towed movement by a tractor comprising: a frame mounted on transversely spaced field ground wheels for forward movement during field operation across ground carrying a crop; a crop engaging system mounted in a transverse direction across a front of the frame so that the frame carries the crop engaging system in the forward direction generally at right angles to the transverse direction into the crop; a hitch arm extending from the frame to a forward end of the hitch arm arranged for attachment to a hitch connector of a tractor by which the frame is towed in the forward direction across the ground while running on the ground wheels; a coupling for connecting the forward end of the hitch arm to a hitch connector of the tractor; the hitch arm being movable so that in the field position the hitch arm extends from the frame generally forwardly for towing the machine in the forward direction and in the transport position the hitch arm extends from one end of the frame generally in the transverse direction for towing the machine in the transverse direction; and a transport assembly attached to the frame for transporting the frame and the crop engaging system carried thereon in the transverse direction towed by the tractor through the hitch arm; the transport assembly comprising: at least one transport ground wheel attached to the frame for engaging the ground and supporting the frame during transport; said at least one transport ground wheel being movable between a field position in which said at least one transport ground wheel is raised from the ground for field operation and a transport position in which said at least one transport ground wheel is in contact with the ground; in the transport position said at least one transport ground wheel being at a position on a forward side of a line in the transverse direction containing the center of gravity of the machine; and an actuation arrangement for moving the hitch arm and said at least one transport ground wheel between the field position and the transport position; the actuation arrangement being arranged to move the hitch arm from the field position to the transport position and to move said at least one transport ground wheel to said position on said forward side of said line such that the machine remains balanced on the hitch arm and said at least one transport wheel while the hitch arm remains attached to the tractor during said movement to said transport position.
 2. The machine according to claim 1 wherein the hitch is a center hitch movable relative to the frame between a first field position inclined forwardly and outwardly toward a first end of the frame to a second field position inclined outwardly and forwardly toward a second end of the frame.
 3. The machine according to claim 1 wherein the crop engaging system comprises a cutter bar.
 4. The machine according to claim 1 wherein the actuation arrangement includes a mechanical link which provides at least part of a mechanical connection between the hitch arm and said one of the transport ground wheels so as to communicate movement of one to the other to provide simultaneous movement thereof relative to the frame.
 5. The machine according to claim 1 wherein the actuation arrangement is adjustable to adjust the angular position of the hitch arm relative to the frame when said one of the transport ground wheels is in transport position.
 6. The machine according to claim 1 wherein there is provided a swivel mounting which is connected to the frame and carries a sub-frame supporting said one of said transport ground wheels for said movement and wherein the actuation arrangement includes an actuator for moving the swivel mounting and a link between the hitch arm and the swivel mounting for connecting said movement of the hitch arm and said one of said ground wheels.
 7. The machine according to claim 6 wherein the swivel mounting moves in a common plane with the hitch arm and the sub-frame is mounted on said swivel mounting for movement about a horizontal axis to lower said at least one transport ground wheel.
 8. The machine according to claim 6 wherein the swivel mounting is actuated by a cylinder connected between the swivel mounting and the frame.
 9. The machine according to claim 6 wherein the link between the swivel mounting and the hitch arm comprises a cylinder operable to adjust the angular position of the hitch arm relative to the swivel mounting and relative to the frame.
 10. The machine according to claim 9 wherein the cylinder is operable to adjust the angular position of the hitch arm relative to the frame when said at least one transport ground wheel is in the transport position.
 11. The machine according to claim 6 wherein the sub-frame carries two transport ground wheels and wherein, in the transport position a first one of the two transport ground wheels is at a position on a forward side of a line in the transverse direction containing the center of gravity of the machine and a second one of the two transport ground wheels is at a position on a rearward side of the line in the transverse direction containing the center of gravity of the machine and wherein said first transport ground wheel is moved to said position on said forward side of said line by rotating the sub-frame about an upstanding axis so as to cause said first one of the wheels to pass underneath said crop engaging system.
 12. A pull-type crop engaging machine for towed movement by a tractor comprising: a frame mounted on transversely spaced field ground wheels for forward movement during field operation across ground carrying a crop; a crop engaging system mounted in a transverse direction across a front of the frame so that the frame carries the crop engaging system in the forward direction generally at right angles to the transverse direction into the crop; a hitch arm extending from the frame to a forward end of the hitch arm arranged for attachment to a hitch connector of a tractor by which the frame is towed in the forward direction across the ground while running on the ground wheels; a coupling for connecting the forward end of the hitch arm to a hitch connector of the tractor; the hitch arm being movable so that in the field position the hitch arm extends from the frame generally forwardly for towing the machine in the forward direction and in the transport position the hitch arm extends from one end of the frame generally in the transverse direction for towing the machine in the transverse direction; and a transport assembly attached to the frame for transporting the frame and the crop engaging system carried thereon in the transverse direction towed by the tractor through the hitch arm; the transport assembly comprising at least one transport ground wheel attached to the frame for engaging the ground and supporting the frame during transport; the transport ground wheel being movable so that in transport position the header is carried on ground wheels on either side of the center of gravity of the machine; and a linkage arrangement connected between the hitch arm and the movable transport ground wheel for causing simultaneous movement relative to the frame of the hitch arm and the movable transport ground wheel while the transport wheel is in contact with the ground.
 13. The machine according to claim 12 wherein the linkage arrangement is adjustable to adjust the angular position of the hitch arm relative to the frame when said movable transport ground wheels is in transport position.
 14. The machine according to claim 13 wherein the linkage arrangement includes a swivel mounting which is connected to the frame and carries the said movable transport ground wheel for said movement and there is provided an actuator for moving the swivel mounting.
 15. The machine according to claim 13 wherein the swivel mounting is actuated by a cylinder connected between the swivel mounting and the frame.
 16. The machine according to claim 13 wherein the link between the swivel mounting and the hitch arm comprises a cylinder operable to adjust the angular position of the hitch arm relative to the swivel mounting and relative to the frame.
 17. The machine according to claim 16 wherein the cylinder is operable to adjust the angular position of the hitch arm relative to the frame when said movable transport ground wheel is in the transport position.
 18. The machine according to claim 13 wherein the swivel mounting moves in a common plane with the hitch and there is provided sub-frame caring said movable transport ground wheel which is mounted on said swivel mounting for movement about a horizontal axis to lower said movable transport ground wheel.
 19. The machine according to claim 18 wherein the sub-frame carries said movable transport ground wheel and a second transport wheel and wherein, in the transport position said movable transport ground wheel is at a position on a forward side of a line in the transverse direction containing the center of gravity of the machine and said second transport ground wheels is at a position on a rearward side of the line in the transverse direction containing the center of gravity of the machine and wherein said movable transport ground wheel is moved to said position on said forward side of said line by rotating the sub-frame about an upstanding axis so as to cause said movable transport ground wheel to pass underneath said crop engaging system. 